Highly Strained Ring Systems. Hydrolysis of endo-Tetracyclo[5.2.0.02,4.03,5]non-8-en-6-yl p-Nitrobenzoate. Importance of Anchimeric Assistance by Bicyclobutane Ring. II

Solvolytic reactivity of endo-tetracyclo[5.2.0.02,4.03,5]non-8-en-6-yl p-nitrobenzoate(1-OPNB), endo-bicyclo-[4.1.0]hept-2-yl p-nitrobenzoate(2-OPNB), and endo-bicyclo[4.2.0]oct-7-en-2-yl p-nitrobenzoate(4-OPNB) was investigated in 50% aqueous acetone. 1-OPNB was less reactive than 2-OPNB that has no cyclobutene ring and more reactive than 4-OPNB that has no bicyclobutane ring. Product study in solvolysis of 1-OPNB was undertaken leading to the rearranged tricyclic alcohol as a major product. The importance of conformational factor for anchimeric assistance by bicyclobutane ring is discussed.