REARRANGEMENT AND DEGRADATION OF BICYCLIC AMINE TETRAALKYLDIBOROXANES.117.

The amine-tetraalkyldiboroxanes C(R7,R7')B(R1)OB(Et)C-(R4)CH2NMe2 [1a: R1,4,7,7' = Et; 1b: R1,4,7 = Et, R7' = Ph; 1b': R4,7,7' = Et, R1 = Ph ; 1c: R1,7,7' = Et, R4 = Ph] react on heating by EtBO elimination and allylborane rearrangement to yield the allyl-aminoboranes Me2NB(Et)CH2 C(R4) = C(R7,7') [2a: R4,7,7' = Et; 2b/2b': R4 = Et, R7,7' = Et, Ph; 2 c: R4 = Ph, R7,7' = Et]: On heating above 60-degrees-C the diastereome ric syn/anti-1d/1d' (1d: R1,7 = C8H14, R4,7' = Et; 1d': R1,7' = C8H14, R4,7 = Et) give the unsaturated rac-amino-trialkyldiboroxane Me2N-B(E t)OBC8H14C(Et)C(ET) = CH2 (rac-3) X-ray structure analysis) by intram olecular 1,2-deaminoboration. rac-3 is characterized by reaction with (Et2BH)2 and (Et2BD)2 with formation of the 1,2,6-oxadiborinane 5 by e volution of H2 or HD respectively. The intramolecular CH-borylation of rac-3 is compared with those of the thujopsen hydrocarbons I-III.