Process for the preparation of β hydroxy-δ lactone using novel intermediates

A process for the preparation of 6-Hydroxy methyl-4-(tert-butyl dimethylsilyloxy)-(4R,6S)-tetra hydro 2H-2-pyranone of formula 1 which comprises

• a) reacting 3-hydroxy-5-(tert.butyldimethylsilyloxy)-(1S,3R,5R)-cyclohexylacetate having formula 5,
• in an organic solvent with chlorochromate of tertiary amines at temperature ranging from 10° C. to 30° C., quenching the reaction by adding diethyl ether, filtering the mixture through celite and washing with brine, removing the solvent by evaporation, followed by fast column filtration to obtain 3-oxo-5-(tert.butyldimethylsilyloxy)-(1S,5S)-cyclohexylacetate having formula 6,
• b) hydrolysing 3-oxo-5-(tert.butyldimethylsilyloxy)-(1S,5S)-cyclohexylacetate having formula 6 with lipase enzyme in a buffer having pH range of 5 to 7, at a temperature ranging from 25 to 30° C. for a period ranging between 24 to 48 hr, extracting the mixture with an organic solvent, removing the solvent by evaporation and on column chromatography to obtain 3-hydroxy-5-(tert-butyldimethyl silyloxy)-(3R,5S)-cyclohexan-1-one having formula 7,
• and
• c) reacting 3-hydroxy-5-(tert-butyldimethyl silyoxy)-(3R,5S)-cyclohexan-1-one having formula 7 with m-chloroperbenzoic acid at room temperature for the period ranging from 16-24 hours, extracting with organic layer, washing with sodium metabisulphite, brine, drying and on evaporation to obtain 6-hydroxymethyl-4-(tertbutyldimethylsilyloxy)-(4S,6R)-tetrahydro-2H-2-pyranone having formula 1