Branched chain alkenyl methyl carbonates, uses thereof in augmenting or enhancing the aroma of perfume compositions, colognes and perfumed articles and formate intermediates useful in preparing same

A mixture produced according to the process of:

• (a) dimerizing isoamylene in order to form a mixture of diisoamylene isomers defined according to the structure:
• ##STR70## wherein R.sub.1 ", R.sub.2 ", R.sub.3 ", R.sub.4 " and R.sub.5 " represent hydrogen or methyl with three of R.sub.1 ", R.sub.2 ", R.sub.3 ", R.sub.4 " and R.sub.5 " representing methyl and the other two of R.sub.1 ", R.sub.2 ", R.sub.3 ", R.sub.4 " and R.sub.5 " representing hydrogen;
• (b) acetylating the resulting diisoamylene derivative with acetic anhydride or an acetyl halide in order to form a mixture of compounds defined according to the structure:
• ##STR71## (c) reducing the resulting compound in order to form a mixture of carbinols defined according to the structure:
• ##STR72## (d) reacting the resulting carbinol with formic acid in order to form a formate defined according to the structure:
• ##STR73## (e) reacting the resulting formate with dimethyl carbonate in order to form the compounds defined according to the structure:
• ##STR74##