A new route for the construction of the AB-ring core of Taxol

Recent Advances in the Synthesis of Cyclobutanes by Olefin [2 + 2] Photocycloaddition Reactions

“…Examples can be found in the synthesis of (±)-jiadifenin by Zhai and co-workers 312 and in a new route for the construction of the AB-ring core of taxol by the Kakiuchi group. 313 …”

Allenes in Catalytic Asymmetric Synthesis and Natural Product Syntheses

“…The skeletal rearrangement of the bicyclo[3.2.0] ketone in the presence of TiCl 4 at room temperature resulted in the formation of a bicyclo[3.2.1]octanone with an isopropylidene bridge (78 % yield). [194] Wards approach towards the total synthesis of (AE)allocyathin B 3 also relies on a [2+2] photocycloaddition of an allene to a bicyclic enone. [195] The photocycloadduct was obtained in up to 87 % yield with a regioselectivity of 4:1 for the desired isomer and was used directly for further manipulation to give the skeletally rearranged tricyclic compound (54-58 % overall yield, Scheme 77).…”

Syntheses and Applications of Functionalized Bicyclo[3.2.1]octanes: Thirteen Years of Progress

“…In this field, Kakiuchi and co-workers have performed an oxidative cleavage of the tetrasubstituted double bond in substrate 494 derived from 368 to give the bicyclic diketone 495 (Scheme 165). 207 In their synthetic studies on taxoids, the groups of Chavan 269 and Spitzner 270 have reported closely related oxidative fragmentation reactions. Alternatively, in their approach to the same ring system, Toyota Contemporaneously, Biju and Rao explored some interesting synthetic routes for the elaboration of polyquinanes and proposed the preparation of the diquinane product 504 by a lead tetraacetate-promoted, selective ring cleavage of diol 503 obtained from 236 (Scheme 167).…”