Patent ID: 6297390
Filing Date: 2001-10-02
Classification: C07D,C11B

Abstract:
A process for the production of optically active 5-methyl-2-(1-methylbutyl)-5-propyl-1,3-dioxane comprising the steps of:(a) forming an N,N-disubstituted lactamide by reacting an enantiomeric lactic acid methyl ester with piperidine or pyrrolidine;(b) forming a protected N,N-disubstituted lactamide by reacting the N,N-disubstituted lactamide with ethyl vinyl ether;(c) forming a protected .alpha.,.beta.-unsaturated ketone by reacting the protected N,N-disubstituted lactamide with 1-propenyl magnesium bromide;(d) forming an unprotected .alpha.,.beta.-unsaturated ketone by removing the protective group;(e) forming an acetal by reacting the unprotected .alpha..beta.-unsaturated ketone with a 1,3-diol;(f) forming a mesylated acetal by reacting the acetal with methane sulfonic chloride;(g) reductively rearranging the mesylated acetal by reaction with diisobutyl aluminum hydride and triethyl to form 5-methyl-2-(1-methylbutenyl)-5-propyl-1,3-dioxane; and(h) reacting the 5-methyl-2(1-methylbutenyl)-5-propyl-1,3-dioxane with hydrogen to form 5-methyl-2-(1-methylbutyl)-5-propyl-1,3-dioxane.