Beilstein J. Org. Chem.2023,19, 325–348, doi:10.3762/bjoc.19.28
. Alongside this, H-B-9-BBN underwent reduction of the ester or lactone 57, to give a hemiacetalintermediate 58, which underwent B‒O/B‒H transborylation with HBpin to give an O-Bpin hemiacetal 59. Borane-mediated collapse of the O-Bpin hemiacetal gave an aldehyde 60 which reacted with the O-Bpin enolate 52
Beilstein J. Org. Chem.2013,9, 476–485, doi:10.3762/bjoc.9.51
. From the 1,3-diol, a bimolecular elimination (TS2) leads to the allylic alcohol as the first channel. In the second channel, the 1,3-diol was converted via TS3 into an unprecedented hemiacetalintermediate, HO–CH2–O–CH(R)–CH2–CH2–OH. This intermediate undergoes ring closure (TS4), affording the 1,3
. Dynamical calculations of a classical trajectory using the atom-centered density matrix propagation molecular dynamics model on the four TSs were carried out, and results of IRC calculations were confirmed by them.
Keywords: DFT calculations; hemiacetalintermediate; hydrogen bond; Prins reaction
) → dioxane(Me), is different from that in Scheme 5. The first difference is the absence of the carbocation X in the former route. The second one is a new hemiacetalintermediate, ether(Me).
Geometries in Figure S1 (Supporting Information File 1) were obtained by IRC calculations starting from TS ones in