The chiral hydrocarbon butylethylmethylpropylmethane (10) has been prepared in a state of known and high optical purity via two independent routes. The first synthesis has as its main feature the addition of 2-thienylmagnesium bromide to the a, p-unsaturated di-(-)-menthyl ester 11. The two diastereoisomeric adducts 12 were readily separated by crystallization, as confirmed by'Hnmr spectroscopy. Saponification gave the thiophene acid 24. Further ...
