Bicyclic compounds solvolysis

Solvolysis of the endo bicyclic compound (24) (X=ONs, p. 446, or Br) gave mostly the bicyclic allylic alcohol (27), along with a smaller amount of the tricyclic alcohol (31), while solvolysis of the exo isomers (28) gave mostly (31), with smaller amounts of 27 Thus the two isomers gave entirely different ratios of products,... 

Fragmentation of quinuclidine derivatives,50-57 in contrast to the same process with aliphatic and bicyclic compounds without nitrogen, gives only one product. The solvolysis of 2-bromo-2-(quinuclidin-3-yl)propane (6) has a stepwise mechanism,50-57 and the degradation of 4-bromoquinuclidine (7) is synchronous.50 53... 

The concerted nature of the reaction is verified by the finding of substantial assistance to ionization (estimated rate enhancements of 104-105) 84 its stereospecificity is shown not only by the experiment already cited, but also by the solvolysis rates of 35 and 36 and of bicyclic compounds 37 and 38.85 Compounds ... 

Expecting that acidic isomerization involving a double Wagner-Meerwein rearrangement would transform the bicyclic olefin 74 into supposedly stable [10.10]betweena-nene and its (Z)[10.10] isomer, they treated 74 with H2S04-AcOH in benzene only to find that the product was an 85 15 mixture of 75 and 76. Solvolysis of the spiro compound 77 was also found to yield a 60 40 mixture of 75 and 76 which was totally free from the fused (Z)[10.10] and ( )[10.10] olefins. 

The cleavage of the ether bond in an oxabicydic compound bearing an oxygen substituent at the bridgehead (i. e. a bicyclic ketal or hemiketal) can be readily accomplished by solvolysis under acidic or basic conditions. 

A comparison of the rates of Sj l solvolysis of the bicyclic compoimds (1) and (2) in acetic acid shows that compound (1) reacts 10" times faster than compound (2). Furthermore, solvolysis of (1) occurs with complete retention of configuration the nucleophile occupies the same position on the one-carbon bridge as did the leaving —OSOjAr group. 

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