Caged structures cyclopropanes

Intramolecular carbene cycloadditions have been used in syntheses of prostanoids, diterpenoids, and other caged structures. Although unlikely to be of great synthetic use, the pyrolyses of the sodium salts of the lactone tosylhydrazones (89) give cyclopropane products via the oxycarbene intermediates as reported in preliminary form last year. ... 

Trimethylene oxide (Hawkins and Davidson, 1966), cyclopropane (Hafemann and Miller, 1969 Majid et al., 1969), and ethylene sulfide (Ripmeester, Personal Communication, May 2,1988) are three molecules that can form in either the 51262 of structure I or the 51264 of structure II as simple hydrates. Raman spectroscopy measurements suggest that a low fraction of 512 cages may also be occupied by cyclopropane at high pressures (Suzuki et al., 2001). Such compounds change structures depending on the temperature and pressure of formation, and guest composition in the aqueous phase as discussed in Section 2.1.3. 

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