Can you show the MECHANISM with arrows of the ENCIRCLED part? with a simple explanation please. Thank you!

01-15 Quinine (Stork) Stork, G., Niu, D.; Fujimoto. A.; Koft, E. R.; Balkovec, J. M.; Tata, J. R.; Dake, G. R. J. Am. Chem. Soc. 2001, 123, 3239. -OSBuPha ostBuPh2 1. Allez-NET (AlMes, Et NH) 2. Me, Bus-ci Imidazole -SiMe, 'Bu 1. LiN Pra, -78 C 2. (CHA) OsiPh Eu 3. TsOH.Py. A 1. Bu,AIH 2. PhyP=CH-OM OME OH NET [Lactone -> CarboxAmide] [O- HO-SiMe, Bu] [CarboxAmide enolate+Alkyl-X] [O-SiMe, Bu-> 0-H) [Lactone -> Lactol] [Wittig-methoxymethyl [Mitsunobu -> Azide] 1. PPhy, DEAD P(O)Oph),N, [Enol -> Aldehyde] 2. HCI, H,0 OSIP Bu OSbuPh Li Meo OsiBuPh OH Ng Meo 1. DMSO. (COCI, NET (85%) 2. PPh , THF, A (819) Meo 70% [Li-Benzyl+Aldehyde) [CompE*-Aldehyde/Azide+M-R] [Alkyl-OH > Ketone) [Ketone -> Imine) [Staudinger] [Imine -> Amine) NaBH. MOH OSiPh, 'Bu Meo Meo H 1. HF, MeCN ch 1. Nah, DMSO Meo 2. Meso,CI, Py OH 2. O H 14:1 [Benzylic oxidation -> Benzyl-OH] [O-SIP Bu -> 0-H] [O-H -> O-SO Me) [N-H -> N-Alkyl] Quinine