Lemarchand, Aude published the artcileSynthesis of chiral ansa-bridged macrocyclic lactams ([16]metacyclophanes) related to geldanamycin, Computed Properties of 99438-28-5, the publication is Synthesis (2005), 1977-1990, database is CAplus.
Two chiral ansa-bridged lactams ([16]metacyclophanes) I (X = CH2, O) were synthesized starting from 2-methoxyhydroquinone diisopropyl ether in 14 (I, X = CH2, 3.9% overall) and 16 synthetic steps (I X = O, 0.6% overall). Both compounds contain typical features of geldanamycin in the C-1 to C-9 part of the ansa chain, i.e. the α,β,γ,δ-unsaturated anilide (C-1 to C-5), the carbamate at the stereogenic carbon atom C-7 and the E-double bond between C-8 and C-9. While the rest of the ansa chain (C-10 to C-15) was an alkyl chain in compound I (X = CH2), a more polar CH2OCH2CH2OCH2 chain was installed in compound I (X = O). Key step of the sequence was a ring-closing metathesis in which the ansa compounds were formed as a mixture of isomers. Deprotection and oxidation to the quinone failed for diisopropyl ether I (X = O) but was successfully conducted with precursor I (X = CH2).
Synthesis published new progress about 99438-28-5. 99438-28-5 belongs to ethers-buliding-blocks, auxiliary class Chiral,Aliphatic cyclic hydrocarbon, name is (+)-B-Methoxydiisopinocampheylborane, and the molecular formula is C21H37BO, Computed Properties of 99438-28-5.
Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem