An efficient and regioselective electrophilic bromolactonization of cyclopropylmethyl diesters using triphenylphosphine sulfide (Ph 3 PS) or diphenyl selenide (Ph 2 Se) as the Lewis basic chalcogenide catalyst has been developed. It was observed that Ph 3 PS favored the formation of antidiastereomer and yielded the multi-functional glactones. Interestingly, the diastereoselectivity was reversed when using Ph 2 Se as a catalyst where the syn-product instead of the anti-product was favored.

Abstract1,3‐difunctionalization of cyclopropane is an useful organic transformation. The corresponding 1,3‐difunctionalized products are synthetic synthons and building blocks in many organic syntheses. Many existing ring‐opening difunctionalization methodologies rely primarily on the use of donor−acceptor cyclopropanes, while the difunctionalization of unactivated cyclopropanes is less exploited. In this research, 1,3‐bromoesterification and 1,3‐bromoetherification of unactivated cyclopropanes were successfully achieved using N‐bromosuccinimide as the brominating agent with high yields and regioselectivity.magnified image