& relationship of the cyclopropane ring relative to the adjacent hydrogen at the ring fusion. When adduct 11 was placed in contact with a sixfold excess of ethereal d&methane, a 4: 1 mixture of two pyrazolines formed during 14 days. These two produced the identical cyclopropane in high yield when photolyzed in ether solution through a Pyrex filter, demonstrating that thev were derived from exclusive addition of diazomeihane to one side ...
