NOVELTY - Synthesis of methyl (2S)-2-(tert-butoxycarbonyl)-amino-2-(-8-azabicyclo(3.2.1)oct-3-yl)-exo-acetate compound (n) comprises: e.g. (ia) converting benzyl 3-oxo-8-azabicyclo(3.2.1)octane-8-carboxylate compound (i) to benzyl 3-exo-formyl-8-azabicyclo(3.2.1)octane-8-carboxylate compound (iii) by converting (i) to oxiranyl compound (ii) by treatment with sodium hydride and trimethylsulfonium iodide in N,N-dimethylformamide and (iia) conversion of (iii) to 1-(2-hydroxy-1-(1R)-phenylethyl amino)-1-(8-(benzyloxy carbonyl)-8-azabicyclo(3.2.1)-oct-3-yl)-exo-methane-1-(1S)-carbonitrile compound (iv).    USE - The compound (n) is used for treating Type II diabetes. No biological data given.    ADVANTAGE - The process is cost effective and eco-friendly.    DETAILED DESCRIPTION - Synthesis of methyl (2S)-2-(tert-butoxycarbonyl)-amino-2-(-8-azabicyclo(3.2.1)oct-3-yl)-exo-acetate compound of formula (n) comprises: either (ia) conversion of benzyl 3-oxo-8-azabicyclo(3.2.1)octane-8-carboxylate compound of formula (i) to benzyl 3-exo-formyl-8-azabicyclo(3.2.1)octane-8-carboxylate compound of formula (iii) by first converting (i) to an oxiranyl compound (ii) by treatment with sodium hydride and trimethylsulfonium iodide in N,N-dimethylformamide at 20-40 degrees C and further to (iii) by treatment with trifluoride-diethyl etherate in dichloromethane at room temperature; (iia) conversion of (iii) to 1-(2-hydroxy-1-(1R)-phenylethyl amino)-1-(8-(benzyloxy carbonyl)-8-azabicyclo(3.2.1)-oct-3-yl)-exo-methane-1-(1S)-carbonitrile compound of formula (iv) following the Strecker synthesis using chiral amine such as R-(-)-2-phenyl glycinol or R-(-)-2-phenylethylamine or their optical isomers as a chiral auxiliary and trimethylsilyl cyanide (TMSCN) as a cyanide source in an organic solvent of dichloromethane, methanol, chloroform, 1,2-ethylenedichloride, hexane, tetrahydrofuran, methyltetrahydrofuran and/or dimethoxyethane in the presence of acetic acid, or Lewis acid at -40 degrees C and 25 degrees C; (iiia) hydrolysis of the nitrile group in (iv) using alcoholic-hydrochloride to obtain 1-(2-hydroxy-1-(1R)-phenylethylamino)-1-(8-(benzyloxycarbonyl)-8-aza-bicyclo-(3.2.1)-oct-3-yl)-exomethane-1-(1S)-carboxylic acid methyl ester hydrochloride compound of formula (v) at room temperature; (iva) conversion of (v) to (2S)-2-amino-2-(8-azabicyclo(3.2.1)oct-3-yl)-exo-acetate hydrochloride compound of formula (vi) by the deprotection of amino group in the presence of palladium supported on charcoal (Pd/C) at around 20 Kg pressure of hydrogen at 60 degrees C in methanolic-hydrochloride; (va) reacting (vi) with benzyl chloroformate in the presence of aqueous saturated sodium bicarbonate solution in aqueous 1,4-dioxane at around 0 degrees C to give methyl (2S)-2-(benzyloxycarbonyl)-amino-2-(-8-(benzyloxy carbonyl)-8-azabicyclo-(3.2.1)oct-3-yl)-exo-acetate compound of formula (vii); and (via) conversion of (vii) to methyl (2S)-2-((tert-butoxycarbonyl)-(benzyloxy carbonyl)-amino)-2-(8-(benzyloxy carbonyl)-8-azabicyclo(3.2.1)oct-3-yl)-exo-acetate compound of formula (viii) using di-tert-butyl dicarbonate and 4-dimethylaminopyridine in an aprotic organic solvent such as acetonitrile at room temperature; or (a) conversion of (i) to benzyl 3-(1-formamido-2-ethoxy-2-(oxo)ethylidene)-8-azabicyclo(3.2.1)-octane-8-carboxylate compound of formula (xii) by the condensation of (i) with an active methylene compounds such as methyl or ethyl isocyanoacetate in the presence of sodium hydride (NaH) in an aprotic solvent such as tetrahydrofuran (THF) or in 1,4-dioxane or any water miscible cyclic ether at 0-10 degrees C; (b) conversion of (xii) to benzyl exo-3-(ethoxy or methoxy (oxo)acetyl)-8-azabicyclo(3.2.1)octane-8-carboxylate compound of formula (xiii) with exo configuration by treatment with methanolic-hydrochloride at around 0 degrees C; (c) conversion of compound of formula (xiii) to 1-(R or S-tert-butylsulfinylamino)-1-(8-(benzyloxy carbonyl)-8-aza-bicyclo(3.2.1)-oct-3-yl)-exo-methanol-(1S)-carboxylic acid methyl ester compound of formula (xv) by first treating compound (xiii) with either (S)-(-)-2-methyl-2-propane sulfinamide or with (R)-(+)-2-methyl-2-propane sulfinamide in the presence of titanium(IV) ethoxide at reflux temperature followed by further reduction of the intermediate ketimine using a suitable reducing agent such as sodium borohydride or sodium triacetoxy borohydride or any modified borohydrides derived from a combination of sodium borohydride with chiral acid such as camphoric acid or tartaric acid or with a chiral acid such as succinic or phthalic acid at room temperature; and (d) conversion of (xv) to compound of formula (m) first by treatment with alcoholic-hydrochloride, followed by treatment with di-tert-butyl dicarbonate, further hydrogenolysis of (m) over palladium supported on charcoal (Pd/C) to give (n), where at each step the intermediates were optionally isolated and purified with suitable process.    R1 = 1-4C alkyl or benzyl;    R = phenyl or benzyloxy (both optionally substituted) or , 1-4C alkyloxy; and    R2 = (R/S)-CasteriskH(Ph)CH2OH, (R/S)-CasteriskH(Ph)CH3, where the asterisk is point of attachment.    INDEPENDENT CLAIMS are included for:    (1) synthesis of methyl (2S)-2-(tert-butoxycarbonyl)-amino-2-(-8-azabicyclo(3.2.1)oct-3-yl)-exoacetate;    (2) benzyl 3-exo-formyl-8-azabicyclo(3.2.1)octane-8-carboxylate (A);    (3) preparation (A);    (4) 1-(2-hydroxy-1-(1R)-phenylethyl amino)-1-(8-(benzyloxy carbonyl)-8-azabicyclo(3.2.1)-oct-3-yl)-exo-methane-1-(1S)-carbonitrile (B) and its salt;    (5) preparation (B);    (6) 1-(2-hydroxy-1-(1R)-phenylethyl amino)-1-(8-(benzyloxy carbonyl)-8-aza-bicyclo(3.2.1)-oct-3-yl)-exo-methane-1-(1S)-carboxylic acid methyl ester (C) and its salt;    (7) preparation (C);    (8) methyl (2S)-2-amino-2-(8-azabicyclo(3.2.1)oct-3-yl)-exo-acetate (D) and its salt;    (9) preparation (D);    (10) methyl (2S)-2-(benzyloxycarbonyl)-amino-2-(-8-(benzyloxy carbonyl)-8-azabicyclo(3.2.1)-oct-3-yl)-exo-acetate (E);    (11) preparation of compound (E);    (12) benzyl methyl (2S)-2-((tert-butoxycarbonyl)-(benzyloxy carbonyl)-amino)-2-(8-(benzyloxy carbonyl)-8-azabicyclo(3.2.1)oct-3-yl)-exo-acetate;    (13) benzyl 3-(1-formamido-2-ethoxy-2-(oxo)ethylidene)-8-azabicyclo(3.2.1)-octane-8-carboxylate;    (14) benzyl exo-3-(ethoxy or methoxy (oxo)acetyl)-8-azabicyclo(3.2.1)octane-8-carboxylate;    (15) synthesis of methyl (2S)-2-(tert-butoxycarbonyl)-amino-2-(-8-(dimethylcarbamoyl)-8-azabicyclo(3.2.1)-oct-3-yl)-exo-acetate compound of formula (o);    (16) synthesis of methyl (2S)-2-(tert-butoxycarbonyl)-amino-2-(-8-(dimethylcarbamoyl)-8-azabicyclo(3.2.1)-oct-3-yl)-exo-acetate; and    (17) synthesis of methyl (2S)-2-(tert-butoxycarbonyl)-amino-2-(-8-azabicyclo(3.2.1)oct-3-yl)-exo-acetate.